When weaving under the arms, here's a video showing how to join vertical edges that were already bound off. I had learn from the New Stitch a Day video but it used darker yarn. I thought this video showed and explained the technique better going through the center of the knit stitch V's on one edge and around the legs of the V on the other edge:
I thought this was a nice video to illustrate how grafting is following a knit stitch:
Love the Zen of Kitchener summary sheet that barbyte posted. The site also has helpful photos for reference, too.
I was wanting to learn the Kitchener stitch w live stitches because I had a project I was needing to add more stockinette stitches in the middle to repair an area. I threaded two reactive life lines above and below and cut across the stitches. I actually cutting my former project in half last night. I'll knit up to the other live stitches held on another cable and will try the Kitchener graft for the first time. I never heard of the Kitchener stitch being used in this manner before but it sounds like this is what Kay might due if she knits up a third sleeve ribbing and Colorwork and grafts it onto the rest of the sleeve she worked. This will be similar to the second video above.